Pre-forming design of P/M superalloy disc based on equipotential field

On the basis of the minimum energy theory and the minimum resistance pressure theory, a new method for the design of die shapes in forging process has been proposed as the equi-potential field method, and it was adopted to design the pre-forming forging shape of a new-type P/M superalloy disc. The isothermal forging of P/M superalloy disc was simulated by MSC/Superform software with six obtained typical die shapes. The stress ratio parameter and strain rate gradient distribution of them in the process of pre-forging and finish-forging were obtained. The relationship curves of stress ratio parameter and deformation degree were established to be used for selecting the best pre-forming forging shape of superalloy disc. Through comparing the stress ratio parameter, the strain rate gradient distribution and the deformation degree, an optimal design for pre-forging die is recommended.